The invention relates to a belt conveyor device of the type for construction machines such as road finishing machines, charging machines, millers, with a continuous conveyor belt that is carried in a conveying plane in a conveying duct by drive and tail pulleys situated inside the conveyor belt, and optionally by support rolls, which are installed in a frame structure defining the conveying duct enclosing the conveyor belt at least at both edge sides.
Construction machines in the form of a road finishing machine are and a charging machine known from the product range 2009 of the company JOSEPH VÖGELE AG, Neckarauerstr. 168-228, 68146 Mannheim Catalog/DE No.: 2129266 DE/02.09, pages 41 and 43, or in road millers known from practice, at least one belt conveyor device is provided each which is embodied as ascending conveyor and contains a continuous conveyor belt carried by internal drive and tail pulleys as well as support rolls. The drive and tail rolls and the support rolls are installed in the frame structure that is possibly covered on all sides. The conveyor belt can be a rubber belt with or without reinforcement, a steel belt or another conveyor belt which normally does not comprise any connecting link but is continuous. The belt conveyor can, for example, have a width of about 1.0 m and extend over a conveying length of about 5.0 m or more, and it is very heavy and relatively complicated to handle in case of a conveyor belt replacement. In case of damage or excessive wear, the conveyor belt must be replaced. In known belt conveyor devices, in most cases the defective conveyor belt is first separated at least one point and then removed from the frame structure to replace the conveyor belt. For this, parts of the frame structure must already be dismounted. To be able to install a spare conveyor belt, all components arranged inside the conveyor belt, i.e. the drive pulley, the tail pulley, the support rolls, and the like, must be first manually removed before the spare conveyor belt can be installed. Then, all these components must be reinstalled. For this, it is common to completely remove the complete drive pulley drive stations, the tail pulley stations, and the support roll stations and the like. Therefore, belt conveyor replacement involves a considerable downtime of the belt conveyor device and a high amount of assembly work.
FR 28 21 833 A relates to a belt conveyor device for conditioning comestible goods. The entire frame structure containing the pulleys and longitudinal stiffening tubes and side rail, in which frame structure the conveyor belt is running, is pivoted manually in joints provided at the longitudinal side of the frame structure in order to facilitate easy cleaning and a conveyor belt replacement. The joints commonly define an axis parallel to the conveying plane and perpendicular to the axes of the pulleys about which axes the frame structure is pivoted upwardly. In order to relieve the conveyor belt, furthermore, an end section of the frame structure can be folded upwardly above an axis parallel to the pulley axes and parallel to the conveying plane. A trail pulley is suspended in the foldable end section. A displacement into the replacement position is executed manually. For belt conveyor devices of construction machines where each pulley may have a weight of about 200 kg and the conveyor belt itself may have a weight minimum 150 kg, the know principle cannot be used.
EP 0 548 661 A discloses a belt conveyor device for conveying various matters e.g. candy goods. The frame structure of the belt conveyor device, containing a trail pulley, a drive pulley and further deflecting rods or trail pulleys is pivoted upwardly relative to a stationarily mounted tensioning pulley about a sidewardly located axis parallel to the conveying plane and perpendicular to the pulley axes. The adjustment into the replacement position is carried out manually by gripping handles of the frame structure. The upwardly pivoted frame structure temporarily may be locked in place. For belt replacement the conveyor belt additionally can be relieved by first pivoting a trail pulley by an eccenter mechanism and by pivoting the conveyor belt with the frame structure relative to the stationarily mounted tensioning pulley.